Thread: main use of references

I wrote c++ program to understand main use of references in the program

Code:

#include<iostream> using namespace std; 
  
int main() 
{ 
  int x = 10;  
  cout << "Location of x = " << &x << endl ; 
  
  int& ref = x;  
  cout << "Location of ref = " << &ref << endl ;
  
  ref = 20; //set ref to 20
  cout << "x = " << x << endl ; 
  cout << "Location of x = " << &x << endl ; 
  cout << "Location of ref = " << &ref << endl ;
 
  x = 30; // set x to 30 
  cout << "ref = " << ref << endl ;
  cout << "Location of x = " << &x << endl ; 
  cout << "Location of ref = " << &ref << endl ;  
  
  return 0; 
}

Location of x = 0x61ff18
Location of ref = 0x61ff18
x = 20
Location of x = 0x61ff18
Location of ref = 0x61ff18
ref = 30
Location of x = 0x61ff18
Location of ref = 0x61ff18

I can't figure out result x and ref variable have same address how it's possible.

I have read pointer and reference are separate both store memory location what are the main difference between pointer and reference

Originally Posted by Zeus_

The FAQs or any other reliable source as
And, if you're looking for real life examples of where references are used, they are used almost everywhere when it comes to writing efficient and optimised code.

I tried to understand with my code
pass by pointer

Code:

#include<iostream> using namespace std; 


void passbypointer(int* x)
{
	*x = 20;
}	
int main() 
{ 
  int a = 10;  
  passbypointer(&a);
  cout << "a = " << a << endl ; 
  
  return 0; 
}

pass by reference

Code:

#include<iostream> using namespace std; 


void passbyreferences(int& x)
{
	x = 20;
}	
int main() 
{ 
  int a = 10;  
  passbyreferences(a);
  cout << "a = " << a << endl ; 
  
  return 0; 
}

but I can't figure out difference between both because they are working in similar way

Originally Posted by laserlight

Yeah, there's no difference. No difference at all.

Let's move on. Pointers and references are the same thing. Yeah, that's right.

... or you could actually read the material that people take the trouble to link you to.

okay understood

-> A reference must always refer to something. Null are not allowed
-> A reference must be initialized when it is created
->once initialized it can not be change with another variable

here is my small input

anyone can correct me if iam wrong

Code:

#include<iostream>



using namespace std;




int main(){
// Variable declaration
 int x = 10;
 
 // Pointer declaration
 int* ref = &x;


 //output the value of x
 cout<<x<<endl;




// Reference: Output the memory address of x


 cout<<ref<<endl;


 // Need to Dereference: Output the value of x before assigning new value


 cout<<*ref<<endl;


 // Change the value of the pointer
 *ref =20;
 // Output the new value of the pointer
 cout<<*ref<<endl;


 // Output the new value of the variable x
 cout<<x<<endl;
return 0;
}